Tourbillon mechanisms for watches have initially been conceived and realised in order to stabilise the rate of the balance by averaging the effects of gravity on the unbalance of the balance. Today balances are well equilibrated, and above all in wrist watches the most important rate variations are caused by amplitude variations of the balance between its horizontal (or flat) and vertical (or pendant) positions. In fact, the amplitude of the oscillations of the balance depends on friction of its shaft in the bearings, the magnitude of these frictions depending on the spatial position of the balance shaft and varying in particular between its vertical and horizontal position.
In an attempt to reduce or average out the effects of the frictional forces acting on the pivots of the balance, new highly complex multiaxial tourbillon systems have been conjured up where the system regulating the watch is made to move within a space of several dimensions relative to a fixed reference system. The Swiss patent CH 693 047, for instance, refers to a watch where the regulating system is housed in a cage executing rotations about a first axis and about a second axis. The patent application EP 1 465 024 A similarly describes a biaxial tourbillon comprising a first conventional cage that contains the balance and the escape pinion, this cage being housed inside a second cage the rotation of which occurs about an axis perpendicular to the axis of rotation of the first cage. However, these tourbillon mechanisms involving two independent rotations of the regulating system remain highly complex and costly for the watch and clockmaker.